17-7445140-G-A

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_000747.3(CHRNB1):c.13G>A(p.Ala5Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000106 in 1,609,076 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000011 ( 0 hom. )

Consequence

CHRNB1
NM_000747.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: -0.234

Variant links:

Genes affected

CHRNB1 (HGNC:1961): (cholinergic receptor nicotinic beta 1 subunit) The muscle acetylcholine receptor is composed of five subunits: two alpha subunits and one beta, one gamma, and one delta subunit. This gene encodes the beta subunit of the acetylcholine receptor. The acetylcholine receptor changes conformation upon acetylcholine binding leading to the opening of an ion-conducting channel across the plasma membrane. Mutations in this gene are associated with slow-channel congenital myasthenic syndrome. [provided by RefSeq, Jul 2008]

CHRNB1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -2 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.11293712).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CHRNB1	NM_000747.3 linkuse as main transcript	c.13G>A	p.Ala5Thr	missense_variant	1/11	ENST00000306071.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CHRNB1	ENST00000306071.7 linkuse as main transcript	c.13G>A	p.Ala5Thr	missense_variant	1/11	1	NM_000747.3	P1	P11230-1
CHRNB1	ENST00000572857.5 linkuse as main transcript	c.13G>A	p.Ala5Thr	missense_variant	1/6	4
CHRNB1	ENST00000574054.1 linkuse as main transcript	n.33G>A		non_coding_transcript_exon_variant	1/2	2

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152264

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000853

AC:

AN:

234396

Hom.:

AF XY:

0.00

AC XY:

AN XY:

129518

show subpopulations

Gnomad AFR exome

AF:

0.0000725

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000966

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000110

AC:

AN:

1456694

Hom.:

Cov.:

AF XY:

0.00000828

AC XY:

AN XY:

724632

show subpopulations

Gnomad4 AFR exome

AF:

0.000180

Gnomad4 AMR exome

AF:

0.0000224

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000630

Gnomad4 OTH exome

AF:

0.0000332

GnomAD4 genome

AF:

0.00000656

AC:

AN:

152382

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74520

show subpopulations

Gnomad4 AFR

AF:

0.0000240

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000113

ExAC

AF:

0.00000831

AC:

Asia WGS

AF:

0.000289

AC:

AN:

3478

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Congenital myasthenic syndrome 2A

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Sep 18, 2023

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Experimental studies and prediction algorithms are not available or were not evaluated, and the functional significance of this variant is currently unknown. ClinVar contains an entry for this variant (Variation ID: 2038566). This variant has not been reported in the literature in individuals affected with CHRNB1-related conditions. The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 5 of the CHRNB1 protein (p.Ala5Thr). -

Inborn genetic diseases

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Aug 21, 2023

The c.13G>A (p.A5T) alteration is located in exon 1 (coding exon 1) of the CHRNB1 gene. This alteration results from a G to A substitution at nucleotide position 13, causing the alanine (A) at amino acid position 5 to be replaced by a threonine (T). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.12

BayesDel_addAF

Benign

-0.067

BayesDel_noAF

Benign

-0.33

Cadd

Benign

Dann

Uncertain

0.99

DEOGEN2

Benign

0.087

T;.

Eigen

Benign

-0.67

Eigen_PC

Benign

-0.59

FATHMM_MKL

Benign

0.38

M_CAP

Benign

0.048

MetaRNN

Benign

0.11

T;T

MetaSVM

Benign

-0.98

MutationAssessor

Benign

1.5

L;.

MutationTaster

Benign

0.98

N;D

PrimateAI

Uncertain

0.55

PROVEAN

Benign

-0.73

N;.

REVEL

Benign

0.19

Sift

Benign

0.29

T;.

Sift4G

Benign

0.29

T;T

Polyphen

0.012

B;.

Vest4

0.24

MutPred

0.39

Gain of glycosylation at A5 (P = 0.0532);Gain of glycosylation at A5 (P = 0.0532);

MVP

0.87

MPC

0.39

ClinPred

0.12

GERP RS

3.4

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.0

Varity_R

0.066

gMVP

0.54

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.0

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over